Keeper substances

The non-volatiles may not possess a signal value themselves but may act as release modulators, or keeper substances. The MUPs in mice provide an example. Each individual expresses at least 4 to 15 different proteins and the combination differs between individuals in the population. Most of the variation between MUPs occurs on the surface of the molecule and is accessible to chemoreceptors. MUPs are stable over the life of the individual. On urine... 

Keeper substances in a scent secretion, and/or the nature of the substrate such as rock, wood or soil, impart longevity to a scent mark. In our own studies, scent marks of captive pronghorn, A. americana, were still noticeable to the human nose 4 months after all animals had been removed from a pen. Similarly, scent marks of the aardwolf, Proteks cristatus, last for up to 6 months (Apps etal, 1989). 2-Phenoxyethanol in the secretions from the chin gland of the rabbit is typical in dominant animals, serving as a fixative to extend the life of the signal (Hayes etal, 2001). 

Keeper substances and commonly used marking substrates such as clay and wood can extend the fade-out time of the signal. Licking or exhaling on scent marks or the body surface of another individual liberates on-demand odors . Alberts (1992a) characterized such signals as having multiple rise times. 

Skill Keeper Answers Opiopeptins Substance P (see Chapters 6 and 17)... 

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